1. Field of the Invention
The present invention relates to a device for aligning articles having different diameters at their heads and tails. More specifically, the present invention relates to a device whereby the heads of such articles are oriented either forwardly or backwardly relative to a selected conveyance direction. In an especially preferred embodiment, the invention relates to a device for aligning liquid-containing capsules, each of which is adapted to fill a cigarette filter in a direction whereby their heads are oriented forwardly relative to the conveyance direction.
2. Description of the Related Art
Accompanying FIG. 6 shows a liquid-containing capsule C which is an example of the articles that may be aligned by a device of the present invention. The capsule C comprises a cylindrical body 1 having a bottom, and a cap 2 for closing an open end of the body 1. The capsule C is filled with liquid or water, for example, and housed in a filter of the cigarette. When the capsule-housed filter of the cigarette is pressed between a user's fingers before it is lit, a part of the capsule C is broken and water in the capsule C flows to enter into fiber filaments in the filter. Components such as tar contained in the smoke can be eliminated by the water among the fiber filaments in the filter to thereby enable the cigarette to exhibit a "lighter" taste.
These capsules C are supplied from the feeder and housed in the filters of cigarettes in the course of manufacturing cigarettes. The capsules C supplied from the feeder are fed in such a manner that their axial direction is aligned with their direction of movement. However, not all of the capsules C may be aligned with their caps located forwardly or backwardly relative to their direction of movement. That is, it is more common that some of the capsules C are oriented with their caps in a forward direction while others are oriented with the caps in a backward direction. This possibility therefore makes it necessary to use a device for aligning them in their direction of movement while at the same time locating their caps in a common direction (e.g. forwardly).
One conventional alignment device uses an optical detector, for example, to detect the position of the cap of each capsule. Those capsules whose caps are located reverse are physically turned over so that they are aligned in the selected direction of movement. However, the optical detector is not entirely reliable in detecting the position of the cap of each capsule supplied and thus it sometimes is mistakenly operated by system "noise".
Another conventional alignment device has a slit at the bottom of a groove through which the capsules are conveyed. This slit has a width larger than the diameter of the body 1 of the capsule C but smaller than that of the cap 2 thereof. The body 1 of each capsule C conveyed through the groove hangs in the slit by its own weight with its cap 2 supported by means of both side rims of the slit. Therefore, all of the capsules C conveyed through the groove are aligned with their caps located in an upward direction. In the case of this conventional alignment device, however, a plurality of the capsules are conveyed through the groove under the condition that they are in contact with one another and are thereby pushed by the following capsules. This potentially causes the capsules to interfere with one another, thereby causing them to fall from the groove.